1. Technical Field
Example embodiments relate to a mobile apparatus, a method of executing a dataflow using the mobile apparatus, a method of context monitoring using the mobile apparatus and a context monitoring system having the mobile apparatus. More particularly, example embodiments relate to a mobile apparatus capable of executing a dataflow efficiently, a method of executing a dataflow using the mobile apparatus, a method of context monitoring using the mobile apparatus and a context monitoring system having the mobile apparatus.
2. Description of the Related Art
Recent paradigm of information communication technology may be a ubiquitous computing, a ubiquitous network, a pervasive computing and so on. “Ubiquitous” means that a user may easily get any desired information anytime and anywhere. In an upcoming ubiquitous age, smart objects, having computing and communication function, may recognize a dynamic environment and be adaptive to the dynamic environment. In other words, the smart objects may have a context awareness feature.
A personal area network (PAN) is one of the core technologies realizing the ubiquitous network having the context awareness feature. The PAN is a network which is provided to a person to communicate in a close range. The person using the PAN may be connected with various devices in about 10 m with respect to the person.
The PAN is suitable for a context monitoring application, which provides proper services in response to an action of the user, a status of the user and an environment around the user. In the PAN environment, the network is operated around the person so that a portable mobile apparatus, capable of receiving data from various sensors and outputting context information to the context monitoring applications, may be a core platform. For example, a mobile terminal may recognize a context of the user by collecting and transmitting the sensed data, and may provide information to the context monitoring application by analyzing the sensed data. The context monitoring application may provide proper services to the user according to the context of the user. Accordingly, the mobile apparatus capable of supporting a number of the context monitoring applications may be necessary.
The context monitoring applications are increasingly emerging and becoming a major workload of the mobile apparatus such as a smart phone. The context monitoring applications continuously monitor contexts of users to provide situation-aware services. Their core is to transform high-rate raw sensed data to context information through a complex series of processing steps. Such a series of processing is commonly represented as a dataflow graph of operators.
The execution of complex context monitoring dataflow may impose significant overhead on the mobile apparatus such as a smart phone, especially considering the resource scarcity of the mobile apparatus supporting context monitoring. Naïve implementation may not be effective in supporting continuous monitoring upon high-rate input sensed data. It easily causes frequent invocation of computation-intensive operators. It may also incur significant overhead in executing and managing the dataflow graphs. With the high CPU overhead, only a small number of context monitoring applications can concurrently run on the mobile apparatus.